A heterogeneous network (Hetnet) is a network formed by cells of different sizes and types, for example, a macro cell, a micro cell, a pico cell, a femto cell, and a cell in a form of a remote radio head (RRH).
In a scenario of intra-frequency deployment of the Hetnet, when user equipment (UE) moves from a micro cell to a macro cell or another micro cell, signal quality of a communication link between the UE and the micro cell decreases. The UE may report a quality up event (1A event) of the macro cell or another micro cell to a network side by using the communication link, and then the UE may receive an active set update (ASU) message that is sent from the network side by using the communication link and used for instructing the UE to add the macro cell or micro cell to an active set. However, because the signal quality of the communication link decreases quickly, the UE may fail to receive the ASU of the network side, thereby failing to add the macro cell or micro cell to the active set, and further causing a cell handover failure of the UE. Therefore, in the prior art, the network side increases a value of an event report evaluation parameter, such as a cell individual offset (CIO), of the macro cell or micro cell, so that the UE can report earlier the 1A event of the macro cell or micro cell and delay reporting a quality down event (1B event), and after reporting the 1B event, still retain the macro cell or micro cell in the active set; in this way, the macro cell or micro cell is added earlier to the active set and deletion of the macro cell or micro cell from the active set is delayed, thereby ensuring a cell handover success rate of the UE.
However, in a case in which the macro cell or micro cell is added to the active set, signal quality of a communication link between the UE and the macro cell or micro cell may be poor, and downlink information received by the UE by using the communication link affects transmission performance of the UE.